1. Field of the Invention
The subject disclosure relates to control systems for helicopters, and more particularly, to a system for predicting rotor torque demand to aid in rotor speed control.
2. Background of the Related Art
To improve engine power management and aid in rotor speed control, modern helicopter engine control systems such as Full Authority Digital Engine Control (FADEC) systems utilize complex algorithms to anticipate a change in power demand. These anticipation algorithms utilize a number of pilot and airframe inputs including collective stick rate, yaw control rate, lateral stick rate and rotor speed rate to predict torque requirements. This feed-forward anticipation approach controls fuel flow to accelerate or decelerate the engine, thereby preventing rotor droop or an over-speed condition from occurring as a result of sudden torque inputs imposed on the rotor blades. There is a need however, to simplify the algorithmic approach presently used to anticipate rotor demand on the engine and reduce the number of inputs required to predict the demand.